The choices of packaging methods, materials and packaging equipments for LED's mainly depend on the factors such as functions, electrical/photoelectric properties, precision, unit price, etc. of LED chips. The LED industry has been developed for several decades, and has gone through the developments of lead LED, chip SMD LED, power LED, high power LED, etc.
When manufacturing a single LED carrier with ceramic materials used as the carrier, it is hard to form circuits on the surface of the carrier; namely, it is hard to form circuit patterns on the carrier. Therefore, there have disadvantages of difficulty in manufacture, poor precision and high cost. If a metal material (such as copper) is used as the carrier, a mask should be made in advance; then, after the procedure of exposure, the unwanted areas are etched by etching so as to form circuit patterns on the carrier. Such a manufacturing method is time-consuming because of the drift of the precision of each mask due to the variability in position thereon. Generally speaking, when a large current passes through a diode die, it is possible that the die may be loosen and even detached or cracked due to the thermal stress effect of the diode die. Therefore, it is indeed an important issue to avoid or reduce the thermal stress.